xref: /openbmc/linux/drivers/spi/spi-s3c64xx.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (c) 2009 Samsung Electronics Co., Ltd.
4 //      Jaswinder Singh <jassi.brar@samsung.com>
5 
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/interrupt.h>
9 #include <linux/delay.h>
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/spi/spi.h>
16 #include <linux/gpio.h>
17 #include <linux/of.h>
18 #include <linux/of_device.h>
19 #include <linux/of_gpio.h>
20 
21 #include <linux/platform_data/spi-s3c64xx.h>
22 
23 #define MAX_SPI_PORTS		6
24 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
25 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
26 #define AUTOSUSPEND_TIMEOUT	2000
27 
28 /* Registers and bit-fields */
29 
30 #define S3C64XX_SPI_CH_CFG		0x00
31 #define S3C64XX_SPI_CLK_CFG		0x04
32 #define S3C64XX_SPI_MODE_CFG		0x08
33 #define S3C64XX_SPI_CS_REG		0x0C
34 #define S3C64XX_SPI_INT_EN		0x10
35 #define S3C64XX_SPI_STATUS		0x14
36 #define S3C64XX_SPI_TX_DATA		0x18
37 #define S3C64XX_SPI_RX_DATA		0x1C
38 #define S3C64XX_SPI_PACKET_CNT		0x20
39 #define S3C64XX_SPI_PENDING_CLR		0x24
40 #define S3C64XX_SPI_SWAP_CFG		0x28
41 #define S3C64XX_SPI_FB_CLK		0x2C
42 
43 #define S3C64XX_SPI_CH_HS_EN		(1<<6)	/* High Speed Enable */
44 #define S3C64XX_SPI_CH_SW_RST		(1<<5)
45 #define S3C64XX_SPI_CH_SLAVE		(1<<4)
46 #define S3C64XX_SPI_CPOL_L		(1<<3)
47 #define S3C64XX_SPI_CPHA_B		(1<<2)
48 #define S3C64XX_SPI_CH_RXCH_ON		(1<<1)
49 #define S3C64XX_SPI_CH_TXCH_ON		(1<<0)
50 
51 #define S3C64XX_SPI_CLKSEL_SRCMSK	(3<<9)
52 #define S3C64XX_SPI_CLKSEL_SRCSHFT	9
53 #define S3C64XX_SPI_ENCLK_ENABLE	(1<<8)
54 #define S3C64XX_SPI_PSR_MASK		0xff
55 
56 #define S3C64XX_SPI_MODE_CH_TSZ_BYTE		(0<<29)
57 #define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD	(1<<29)
58 #define S3C64XX_SPI_MODE_CH_TSZ_WORD		(2<<29)
59 #define S3C64XX_SPI_MODE_CH_TSZ_MASK		(3<<29)
60 #define S3C64XX_SPI_MODE_BUS_TSZ_BYTE		(0<<17)
61 #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD	(1<<17)
62 #define S3C64XX_SPI_MODE_BUS_TSZ_WORD		(2<<17)
63 #define S3C64XX_SPI_MODE_BUS_TSZ_MASK		(3<<17)
64 #define S3C64XX_SPI_MODE_RXDMA_ON		(1<<2)
65 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
66 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
67 
68 #define S3C64XX_SPI_CS_NSC_CNT_2		(2<<4)
69 #define S3C64XX_SPI_CS_AUTO			(1<<1)
70 #define S3C64XX_SPI_CS_SIG_INACT		(1<<0)
71 
72 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
73 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
74 #define S3C64XX_SPI_INT_RX_UNDERRUN_EN		(1<<4)
75 #define S3C64XX_SPI_INT_TX_OVERRUN_EN		(1<<3)
76 #define S3C64XX_SPI_INT_TX_UNDERRUN_EN		(1<<2)
77 #define S3C64XX_SPI_INT_RX_FIFORDY_EN		(1<<1)
78 #define S3C64XX_SPI_INT_TX_FIFORDY_EN		(1<<0)
79 
80 #define S3C64XX_SPI_ST_RX_OVERRUN_ERR		(1<<5)
81 #define S3C64XX_SPI_ST_RX_UNDERRUN_ERR		(1<<4)
82 #define S3C64XX_SPI_ST_TX_OVERRUN_ERR		(1<<3)
83 #define S3C64XX_SPI_ST_TX_UNDERRUN_ERR		(1<<2)
84 #define S3C64XX_SPI_ST_RX_FIFORDY		(1<<1)
85 #define S3C64XX_SPI_ST_TX_FIFORDY		(1<<0)
86 
87 #define S3C64XX_SPI_PACKET_CNT_EN		(1<<16)
88 
89 #define S3C64XX_SPI_PND_TX_UNDERRUN_CLR		(1<<4)
90 #define S3C64XX_SPI_PND_TX_OVERRUN_CLR		(1<<3)
91 #define S3C64XX_SPI_PND_RX_UNDERRUN_CLR		(1<<2)
92 #define S3C64XX_SPI_PND_RX_OVERRUN_CLR		(1<<1)
93 #define S3C64XX_SPI_PND_TRAILING_CLR		(1<<0)
94 
95 #define S3C64XX_SPI_SWAP_RX_HALF_WORD		(1<<7)
96 #define S3C64XX_SPI_SWAP_RX_BYTE		(1<<6)
97 #define S3C64XX_SPI_SWAP_RX_BIT			(1<<5)
98 #define S3C64XX_SPI_SWAP_RX_EN			(1<<4)
99 #define S3C64XX_SPI_SWAP_TX_HALF_WORD		(1<<3)
100 #define S3C64XX_SPI_SWAP_TX_BYTE		(1<<2)
101 #define S3C64XX_SPI_SWAP_TX_BIT			(1<<1)
102 #define S3C64XX_SPI_SWAP_TX_EN			(1<<0)
103 
104 #define S3C64XX_SPI_FBCLK_MSK			(3<<0)
105 
106 #define FIFO_LVL_MASK(i) ((i)->port_conf->fifo_lvl_mask[i->port_id])
107 #define S3C64XX_SPI_ST_TX_DONE(v, i) (((v) & \
108 				(1 << (i)->port_conf->tx_st_done)) ? 1 : 0)
109 #define TX_FIFO_LVL(v, i) (((v) >> 6) & FIFO_LVL_MASK(i))
110 #define RX_FIFO_LVL(v, i) (((v) >> (i)->port_conf->rx_lvl_offset) & \
111 					FIFO_LVL_MASK(i))
112 
113 #define S3C64XX_SPI_MAX_TRAILCNT	0x3ff
114 #define S3C64XX_SPI_TRAILCNT_OFF	19
115 
116 #define S3C64XX_SPI_TRAILCNT		S3C64XX_SPI_MAX_TRAILCNT
117 
118 #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
119 #define is_polling(x)	(x->port_conf->quirks & S3C64XX_SPI_QUIRK_POLL)
120 
121 #define RXBUSY    (1<<2)
122 #define TXBUSY    (1<<3)
123 
124 struct s3c64xx_spi_dma_data {
125 	struct dma_chan *ch;
126 	dma_cookie_t cookie;
127 	enum dma_transfer_direction direction;
128 };
129 
130 /**
131  * struct s3c64xx_spi_port_config - SPI Controller hardware info
132  * @fifo_lvl_mask: Bit-mask for {TX|RX}_FIFO_LVL bits in SPI_STATUS register.
133  * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
134  * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
135  * @quirks: Bitmask of known quirks
136  * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
137  * @clk_from_cmu: True, if the controller does not include a clock mux and
138  *	prescaler unit.
139  * @clk_ioclk: True if clock is present on this device
140  *
141  * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but
142  * differ in some aspects such as the size of the fifo and spi bus clock
143  * setup. Such differences are specified to the driver using this structure
144  * which is provided as driver data to the driver.
145  */
146 struct s3c64xx_spi_port_config {
147 	int	fifo_lvl_mask[MAX_SPI_PORTS];
148 	int	rx_lvl_offset;
149 	int	tx_st_done;
150 	int	quirks;
151 	bool	high_speed;
152 	bool	clk_from_cmu;
153 	bool	clk_ioclk;
154 };
155 
156 /**
157  * struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
158  * @clk: Pointer to the spi clock.
159  * @src_clk: Pointer to the clock used to generate SPI signals.
160  * @ioclk: Pointer to the i/o clock between master and slave
161  * @pdev: Pointer to device's platform device data
162  * @master: Pointer to the SPI Protocol master.
163  * @cntrlr_info: Platform specific data for the controller this driver manages.
164  * @lock: Controller specific lock.
165  * @state: Set of FLAGS to indicate status.
166  * @sfr_start: BUS address of SPI controller regs.
167  * @regs: Pointer to ioremap'ed controller registers.
168  * @xfer_completion: To indicate completion of xfer task.
169  * @cur_mode: Stores the active configuration of the controller.
170  * @cur_bpw: Stores the active bits per word settings.
171  * @cur_speed: Current clock speed
172  * @rx_dma: Local receive DMA data (e.g. chan and direction)
173  * @tx_dma: Local transmit DMA data (e.g. chan and direction)
174  * @port_conf: Local SPI port configuartion data
175  * @port_id: Port identification number
176  */
177 struct s3c64xx_spi_driver_data {
178 	void __iomem                    *regs;
179 	struct clk                      *clk;
180 	struct clk                      *src_clk;
181 	struct clk                      *ioclk;
182 	struct platform_device          *pdev;
183 	struct spi_master               *master;
184 	struct s3c64xx_spi_info         *cntrlr_info;
185 	spinlock_t                      lock;
186 	unsigned long                   sfr_start;
187 	struct completion               xfer_completion;
188 	unsigned                        state;
189 	unsigned                        cur_mode, cur_bpw;
190 	unsigned                        cur_speed;
191 	struct s3c64xx_spi_dma_data	rx_dma;
192 	struct s3c64xx_spi_dma_data	tx_dma;
193 	const struct s3c64xx_spi_port_config	*port_conf;
194 	unsigned int			port_id;
195 };
196 
197 static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
198 {
199 	void __iomem *regs = sdd->regs;
200 	unsigned long loops;
201 	u32 val;
202 
203 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
204 
205 	val = readl(regs + S3C64XX_SPI_CH_CFG);
206 	val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
207 	writel(val, regs + S3C64XX_SPI_CH_CFG);
208 
209 	val = readl(regs + S3C64XX_SPI_CH_CFG);
210 	val |= S3C64XX_SPI_CH_SW_RST;
211 	val &= ~S3C64XX_SPI_CH_HS_EN;
212 	writel(val, regs + S3C64XX_SPI_CH_CFG);
213 
214 	/* Flush TxFIFO*/
215 	loops = msecs_to_loops(1);
216 	do {
217 		val = readl(regs + S3C64XX_SPI_STATUS);
218 	} while (TX_FIFO_LVL(val, sdd) && loops--);
219 
220 	if (loops == 0)
221 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
222 
223 	/* Flush RxFIFO*/
224 	loops = msecs_to_loops(1);
225 	do {
226 		val = readl(regs + S3C64XX_SPI_STATUS);
227 		if (RX_FIFO_LVL(val, sdd))
228 			readl(regs + S3C64XX_SPI_RX_DATA);
229 		else
230 			break;
231 	} while (loops--);
232 
233 	if (loops == 0)
234 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
235 
236 	val = readl(regs + S3C64XX_SPI_CH_CFG);
237 	val &= ~S3C64XX_SPI_CH_SW_RST;
238 	writel(val, regs + S3C64XX_SPI_CH_CFG);
239 
240 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
241 	val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
242 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
243 }
244 
245 static void s3c64xx_spi_dmacb(void *data)
246 {
247 	struct s3c64xx_spi_driver_data *sdd;
248 	struct s3c64xx_spi_dma_data *dma = data;
249 	unsigned long flags;
250 
251 	if (dma->direction == DMA_DEV_TO_MEM)
252 		sdd = container_of(data,
253 			struct s3c64xx_spi_driver_data, rx_dma);
254 	else
255 		sdd = container_of(data,
256 			struct s3c64xx_spi_driver_data, tx_dma);
257 
258 	spin_lock_irqsave(&sdd->lock, flags);
259 
260 	if (dma->direction == DMA_DEV_TO_MEM) {
261 		sdd->state &= ~RXBUSY;
262 		if (!(sdd->state & TXBUSY))
263 			complete(&sdd->xfer_completion);
264 	} else {
265 		sdd->state &= ~TXBUSY;
266 		if (!(sdd->state & RXBUSY))
267 			complete(&sdd->xfer_completion);
268 	}
269 
270 	spin_unlock_irqrestore(&sdd->lock, flags);
271 }
272 
273 static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
274 			struct sg_table *sgt)
275 {
276 	struct s3c64xx_spi_driver_data *sdd;
277 	struct dma_slave_config config;
278 	struct dma_async_tx_descriptor *desc;
279 	int ret;
280 
281 	memset(&config, 0, sizeof(config));
282 
283 	if (dma->direction == DMA_DEV_TO_MEM) {
284 		sdd = container_of((void *)dma,
285 			struct s3c64xx_spi_driver_data, rx_dma);
286 		config.direction = dma->direction;
287 		config.src_addr = sdd->sfr_start + S3C64XX_SPI_RX_DATA;
288 		config.src_addr_width = sdd->cur_bpw / 8;
289 		config.src_maxburst = 1;
290 		dmaengine_slave_config(dma->ch, &config);
291 	} else {
292 		sdd = container_of((void *)dma,
293 			struct s3c64xx_spi_driver_data, tx_dma);
294 		config.direction = dma->direction;
295 		config.dst_addr = sdd->sfr_start + S3C64XX_SPI_TX_DATA;
296 		config.dst_addr_width = sdd->cur_bpw / 8;
297 		config.dst_maxburst = 1;
298 		dmaengine_slave_config(dma->ch, &config);
299 	}
300 
301 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
302 				       dma->direction, DMA_PREP_INTERRUPT);
303 	if (!desc) {
304 		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
305 			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
306 		return -ENOMEM;
307 	}
308 
309 	desc->callback = s3c64xx_spi_dmacb;
310 	desc->callback_param = dma;
311 
312 	dma->cookie = dmaengine_submit(desc);
313 	ret = dma_submit_error(dma->cookie);
314 	if (ret) {
315 		dev_err(&sdd->pdev->dev, "DMA submission failed");
316 		return -EIO;
317 	}
318 
319 	dma_async_issue_pending(dma->ch);
320 	return 0;
321 }
322 
323 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
324 {
325 	struct s3c64xx_spi_driver_data *sdd =
326 					spi_master_get_devdata(spi->master);
327 
328 	if (sdd->cntrlr_info->no_cs)
329 		return;
330 
331 	if (enable) {
332 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
333 			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
334 		} else {
335 			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
336 
337 			ssel |= (S3C64XX_SPI_CS_AUTO |
338 						S3C64XX_SPI_CS_NSC_CNT_2);
339 			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
340 		}
341 	} else {
342 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
343 			writel(S3C64XX_SPI_CS_SIG_INACT,
344 			       sdd->regs + S3C64XX_SPI_CS_REG);
345 	}
346 }
347 
348 static int s3c64xx_spi_prepare_transfer(struct spi_master *spi)
349 {
350 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(spi);
351 
352 	if (is_polling(sdd))
353 		return 0;
354 
355 	spi->dma_rx = sdd->rx_dma.ch;
356 	spi->dma_tx = sdd->tx_dma.ch;
357 
358 	return 0;
359 }
360 
361 static bool s3c64xx_spi_can_dma(struct spi_master *master,
362 				struct spi_device *spi,
363 				struct spi_transfer *xfer)
364 {
365 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
366 
367 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
368 }
369 
370 static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
371 				    struct spi_transfer *xfer, int dma_mode)
372 {
373 	void __iomem *regs = sdd->regs;
374 	u32 modecfg, chcfg;
375 	int ret = 0;
376 
377 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
378 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
379 
380 	chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
381 	chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
382 
383 	if (dma_mode) {
384 		chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
385 	} else {
386 		/* Always shift in data in FIFO, even if xfer is Tx only,
387 		 * this helps setting PCKT_CNT value for generating clocks
388 		 * as exactly needed.
389 		 */
390 		chcfg |= S3C64XX_SPI_CH_RXCH_ON;
391 		writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
392 					| S3C64XX_SPI_PACKET_CNT_EN,
393 					regs + S3C64XX_SPI_PACKET_CNT);
394 	}
395 
396 	if (xfer->tx_buf != NULL) {
397 		sdd->state |= TXBUSY;
398 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
399 		if (dma_mode) {
400 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
401 			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
402 		} else {
403 			switch (sdd->cur_bpw) {
404 			case 32:
405 				iowrite32_rep(regs + S3C64XX_SPI_TX_DATA,
406 					xfer->tx_buf, xfer->len / 4);
407 				break;
408 			case 16:
409 				iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
410 					xfer->tx_buf, xfer->len / 2);
411 				break;
412 			default:
413 				iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
414 					xfer->tx_buf, xfer->len);
415 				break;
416 			}
417 		}
418 	}
419 
420 	if (xfer->rx_buf != NULL) {
421 		sdd->state |= RXBUSY;
422 
423 		if (sdd->port_conf->high_speed && sdd->cur_speed >= 30000000UL
424 					&& !(sdd->cur_mode & SPI_CPHA))
425 			chcfg |= S3C64XX_SPI_CH_HS_EN;
426 
427 		if (dma_mode) {
428 			modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
429 			chcfg |= S3C64XX_SPI_CH_RXCH_ON;
430 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
431 					| S3C64XX_SPI_PACKET_CNT_EN,
432 					regs + S3C64XX_SPI_PACKET_CNT);
433 			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
434 		}
435 	}
436 
437 	if (ret)
438 		return ret;
439 
440 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
441 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
442 
443 	return 0;
444 }
445 
446 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
447 					int timeout_ms)
448 {
449 	void __iomem *regs = sdd->regs;
450 	unsigned long val = 1;
451 	u32 status;
452 
453 	/* max fifo depth available */
454 	u32 max_fifo = (FIFO_LVL_MASK(sdd) >> 1) + 1;
455 
456 	if (timeout_ms)
457 		val = msecs_to_loops(timeout_ms);
458 
459 	do {
460 		status = readl(regs + S3C64XX_SPI_STATUS);
461 	} while (RX_FIFO_LVL(status, sdd) < max_fifo && --val);
462 
463 	/* return the actual received data length */
464 	return RX_FIFO_LVL(status, sdd);
465 }
466 
467 static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
468 				struct spi_transfer *xfer)
469 {
470 	void __iomem *regs = sdd->regs;
471 	unsigned long val;
472 	u32 status;
473 	int ms;
474 
475 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
476 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
477 	ms += 30;               /* some tolerance */
478 	ms = max(ms, 100);      /* minimum timeout */
479 
480 	val = msecs_to_jiffies(ms) + 10;
481 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
482 
483 	/*
484 	 * If the previous xfer was completed within timeout, then
485 	 * proceed further else return -EIO.
486 	 * DmaTx returns after simply writing data in the FIFO,
487 	 * w/o waiting for real transmission on the bus to finish.
488 	 * DmaRx returns only after Dma read data from FIFO which
489 	 * needs bus transmission to finish, so we don't worry if
490 	 * Xfer involved Rx(with or without Tx).
491 	 */
492 	if (val && !xfer->rx_buf) {
493 		val = msecs_to_loops(10);
494 		status = readl(regs + S3C64XX_SPI_STATUS);
495 		while ((TX_FIFO_LVL(status, sdd)
496 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
497 		       && --val) {
498 			cpu_relax();
499 			status = readl(regs + S3C64XX_SPI_STATUS);
500 		}
501 
502 	}
503 
504 	/* If timed out while checking rx/tx status return error */
505 	if (!val)
506 		return -EIO;
507 
508 	return 0;
509 }
510 
511 static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
512 				struct spi_transfer *xfer)
513 {
514 	void __iomem *regs = sdd->regs;
515 	unsigned long val;
516 	u32 status;
517 	int loops;
518 	u32 cpy_len;
519 	u8 *buf;
520 	int ms;
521 
522 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
523 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
524 	ms += 10; /* some tolerance */
525 
526 	val = msecs_to_loops(ms);
527 	do {
528 		status = readl(regs + S3C64XX_SPI_STATUS);
529 	} while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
530 
531 	if (!val)
532 		return -EIO;
533 
534 	/* If it was only Tx */
535 	if (!xfer->rx_buf) {
536 		sdd->state &= ~TXBUSY;
537 		return 0;
538 	}
539 
540 	/*
541 	 * If the receive length is bigger than the controller fifo
542 	 * size, calculate the loops and read the fifo as many times.
543 	 * loops = length / max fifo size (calculated by using the
544 	 * fifo mask).
545 	 * For any size less than the fifo size the below code is
546 	 * executed atleast once.
547 	 */
548 	loops = xfer->len / ((FIFO_LVL_MASK(sdd) >> 1) + 1);
549 	buf = xfer->rx_buf;
550 	do {
551 		/* wait for data to be received in the fifo */
552 		cpy_len = s3c64xx_spi_wait_for_timeout(sdd,
553 						       (loops ? ms : 0));
554 
555 		switch (sdd->cur_bpw) {
556 		case 32:
557 			ioread32_rep(regs + S3C64XX_SPI_RX_DATA,
558 				     buf, cpy_len / 4);
559 			break;
560 		case 16:
561 			ioread16_rep(regs + S3C64XX_SPI_RX_DATA,
562 				     buf, cpy_len / 2);
563 			break;
564 		default:
565 			ioread8_rep(regs + S3C64XX_SPI_RX_DATA,
566 				    buf, cpy_len);
567 			break;
568 		}
569 
570 		buf = buf + cpy_len;
571 	} while (loops--);
572 	sdd->state &= ~RXBUSY;
573 
574 	return 0;
575 }
576 
577 static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
578 {
579 	void __iomem *regs = sdd->regs;
580 	int ret;
581 	u32 val;
582 
583 	/* Disable Clock */
584 	if (!sdd->port_conf->clk_from_cmu) {
585 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
586 		val &= ~S3C64XX_SPI_ENCLK_ENABLE;
587 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
588 	}
589 
590 	/* Set Polarity and Phase */
591 	val = readl(regs + S3C64XX_SPI_CH_CFG);
592 	val &= ~(S3C64XX_SPI_CH_SLAVE |
593 			S3C64XX_SPI_CPOL_L |
594 			S3C64XX_SPI_CPHA_B);
595 
596 	if (sdd->cur_mode & SPI_CPOL)
597 		val |= S3C64XX_SPI_CPOL_L;
598 
599 	if (sdd->cur_mode & SPI_CPHA)
600 		val |= S3C64XX_SPI_CPHA_B;
601 
602 	writel(val, regs + S3C64XX_SPI_CH_CFG);
603 
604 	/* Set Channel & DMA Mode */
605 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
606 	val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
607 			| S3C64XX_SPI_MODE_CH_TSZ_MASK);
608 
609 	switch (sdd->cur_bpw) {
610 	case 32:
611 		val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
612 		val |= S3C64XX_SPI_MODE_CH_TSZ_WORD;
613 		break;
614 	case 16:
615 		val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
616 		val |= S3C64XX_SPI_MODE_CH_TSZ_HALFWORD;
617 		break;
618 	default:
619 		val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
620 		val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE;
621 		break;
622 	}
623 
624 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
625 
626 	if (sdd->port_conf->clk_from_cmu) {
627 		/* The src_clk clock is divided internally by 2 */
628 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
629 		if (ret)
630 			return ret;
631 		sdd->cur_speed = clk_get_rate(sdd->src_clk) / 2;
632 	} else {
633 		/* Configure Clock */
634 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
635 		val &= ~S3C64XX_SPI_PSR_MASK;
636 		val |= ((clk_get_rate(sdd->src_clk) / sdd->cur_speed / 2 - 1)
637 				& S3C64XX_SPI_PSR_MASK);
638 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
639 
640 		/* Enable Clock */
641 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
642 		val |= S3C64XX_SPI_ENCLK_ENABLE;
643 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
644 	}
645 
646 	return 0;
647 }
648 
649 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
650 
651 static int s3c64xx_spi_prepare_message(struct spi_master *master,
652 				       struct spi_message *msg)
653 {
654 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
655 	struct spi_device *spi = msg->spi;
656 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
657 
658 	/* Configure feedback delay */
659 	writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
660 
661 	return 0;
662 }
663 
664 static int s3c64xx_spi_transfer_one(struct spi_master *master,
665 				    struct spi_device *spi,
666 				    struct spi_transfer *xfer)
667 {
668 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
669 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
670 	const void *tx_buf = NULL;
671 	void *rx_buf = NULL;
672 	int target_len = 0, origin_len = 0;
673 	int use_dma = 0;
674 	int status;
675 	u32 speed;
676 	u8 bpw;
677 	unsigned long flags;
678 
679 	reinit_completion(&sdd->xfer_completion);
680 
681 	/* Only BPW and Speed may change across transfers */
682 	bpw = xfer->bits_per_word;
683 	speed = xfer->speed_hz;
684 
685 	if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
686 		sdd->cur_bpw = bpw;
687 		sdd->cur_speed = speed;
688 		sdd->cur_mode = spi->mode;
689 		status = s3c64xx_spi_config(sdd);
690 		if (status)
691 			return status;
692 	}
693 
694 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
695 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
696 		use_dma = 1;
697 
698 	} else if (is_polling(sdd) && xfer->len > fifo_len) {
699 		tx_buf = xfer->tx_buf;
700 		rx_buf = xfer->rx_buf;
701 		origin_len = xfer->len;
702 
703 		target_len = xfer->len;
704 		if (xfer->len > fifo_len)
705 			xfer->len = fifo_len;
706 	}
707 
708 	do {
709 		spin_lock_irqsave(&sdd->lock, flags);
710 
711 		/* Pending only which is to be done */
712 		sdd->state &= ~RXBUSY;
713 		sdd->state &= ~TXBUSY;
714 
715 		/* Start the signals */
716 		s3c64xx_spi_set_cs(spi, true);
717 
718 		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
719 
720 		spin_unlock_irqrestore(&sdd->lock, flags);
721 
722 		if (status) {
723 			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
724 			break;
725 		}
726 
727 		if (use_dma)
728 			status = s3c64xx_wait_for_dma(sdd, xfer);
729 		else
730 			status = s3c64xx_wait_for_pio(sdd, xfer);
731 
732 		if (status) {
733 			dev_err(&spi->dev,
734 				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
735 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
736 				(sdd->state & RXBUSY) ? 'f' : 'p',
737 				(sdd->state & TXBUSY) ? 'f' : 'p',
738 				xfer->len, use_dma ? 1 : 0, status);
739 
740 			if (use_dma) {
741 				struct dma_tx_state s;
742 
743 				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
744 					dmaengine_pause(sdd->tx_dma.ch);
745 					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
746 					dmaengine_terminate_all(sdd->tx_dma.ch);
747 					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
748 
749 				}
750 				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
751 					dmaengine_pause(sdd->rx_dma.ch);
752 					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
753 					dmaengine_terminate_all(sdd->rx_dma.ch);
754 					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
755 				}
756 			}
757 		} else {
758 			s3c64xx_flush_fifo(sdd);
759 		}
760 		if (target_len > 0) {
761 			target_len -= xfer->len;
762 
763 			if (xfer->tx_buf)
764 				xfer->tx_buf += xfer->len;
765 
766 			if (xfer->rx_buf)
767 				xfer->rx_buf += xfer->len;
768 
769 			if (target_len > fifo_len)
770 				xfer->len = fifo_len;
771 			else
772 				xfer->len = target_len;
773 		}
774 	} while (target_len > 0);
775 
776 	if (origin_len) {
777 		/* Restore original xfer buffers and length */
778 		xfer->tx_buf = tx_buf;
779 		xfer->rx_buf = rx_buf;
780 		xfer->len = origin_len;
781 	}
782 
783 	return status;
784 }
785 
786 static struct s3c64xx_spi_csinfo *s3c64xx_get_slave_ctrldata(
787 				struct spi_device *spi)
788 {
789 	struct s3c64xx_spi_csinfo *cs;
790 	struct device_node *slave_np, *data_np = NULL;
791 	u32 fb_delay = 0;
792 
793 	slave_np = spi->dev.of_node;
794 	if (!slave_np) {
795 		dev_err(&spi->dev, "device node not found\n");
796 		return ERR_PTR(-EINVAL);
797 	}
798 
799 	data_np = of_get_child_by_name(slave_np, "controller-data");
800 	if (!data_np) {
801 		dev_err(&spi->dev, "child node 'controller-data' not found\n");
802 		return ERR_PTR(-EINVAL);
803 	}
804 
805 	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
806 	if (!cs) {
807 		of_node_put(data_np);
808 		return ERR_PTR(-ENOMEM);
809 	}
810 
811 	of_property_read_u32(data_np, "samsung,spi-feedback-delay", &fb_delay);
812 	cs->fb_delay = fb_delay;
813 	of_node_put(data_np);
814 	return cs;
815 }
816 
817 /*
818  * Here we only check the validity of requested configuration
819  * and save the configuration in a local data-structure.
820  * The controller is actually configured only just before we
821  * get a message to transfer.
822  */
823 static int s3c64xx_spi_setup(struct spi_device *spi)
824 {
825 	struct s3c64xx_spi_csinfo *cs = spi->controller_data;
826 	struct s3c64xx_spi_driver_data *sdd;
827 	int err;
828 
829 	sdd = spi_master_get_devdata(spi->master);
830 	if (spi->dev.of_node) {
831 		cs = s3c64xx_get_slave_ctrldata(spi);
832 		spi->controller_data = cs;
833 	} else if (cs) {
834 		/* On non-DT platforms the SPI core will set spi->cs_gpio
835 		 * to -ENOENT. The GPIO pin used to drive the chip select
836 		 * is defined by using platform data so spi->cs_gpio value
837 		 * has to be override to have the proper GPIO pin number.
838 		 */
839 		spi->cs_gpio = cs->line;
840 	}
841 
842 	if (IS_ERR_OR_NULL(cs)) {
843 		dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
844 		return -ENODEV;
845 	}
846 
847 	if (!spi_get_ctldata(spi)) {
848 		if (gpio_is_valid(spi->cs_gpio)) {
849 			err = gpio_request_one(spi->cs_gpio, GPIOF_OUT_INIT_HIGH,
850 					       dev_name(&spi->dev));
851 			if (err) {
852 				dev_err(&spi->dev,
853 					"Failed to get /CS gpio [%d]: %d\n",
854 					spi->cs_gpio, err);
855 				goto err_gpio_req;
856 			}
857 		}
858 
859 		spi_set_ctldata(spi, cs);
860 	}
861 
862 	pm_runtime_get_sync(&sdd->pdev->dev);
863 
864 	/* Check if we can provide the requested rate */
865 	if (!sdd->port_conf->clk_from_cmu) {
866 		u32 psr, speed;
867 
868 		/* Max possible */
869 		speed = clk_get_rate(sdd->src_clk) / 2 / (0 + 1);
870 
871 		if (spi->max_speed_hz > speed)
872 			spi->max_speed_hz = speed;
873 
874 		psr = clk_get_rate(sdd->src_clk) / 2 / spi->max_speed_hz - 1;
875 		psr &= S3C64XX_SPI_PSR_MASK;
876 		if (psr == S3C64XX_SPI_PSR_MASK)
877 			psr--;
878 
879 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
880 		if (spi->max_speed_hz < speed) {
881 			if (psr+1 < S3C64XX_SPI_PSR_MASK) {
882 				psr++;
883 			} else {
884 				err = -EINVAL;
885 				goto setup_exit;
886 			}
887 		}
888 
889 		speed = clk_get_rate(sdd->src_clk) / 2 / (psr + 1);
890 		if (spi->max_speed_hz >= speed) {
891 			spi->max_speed_hz = speed;
892 		} else {
893 			dev_err(&spi->dev, "Can't set %dHz transfer speed\n",
894 				spi->max_speed_hz);
895 			err = -EINVAL;
896 			goto setup_exit;
897 		}
898 	}
899 
900 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
901 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
902 	s3c64xx_spi_set_cs(spi, false);
903 
904 	return 0;
905 
906 setup_exit:
907 	pm_runtime_mark_last_busy(&sdd->pdev->dev);
908 	pm_runtime_put_autosuspend(&sdd->pdev->dev);
909 	/* setup() returns with device de-selected */
910 	s3c64xx_spi_set_cs(spi, false);
911 
912 	if (gpio_is_valid(spi->cs_gpio))
913 		gpio_free(spi->cs_gpio);
914 	spi_set_ctldata(spi, NULL);
915 
916 err_gpio_req:
917 	if (spi->dev.of_node)
918 		kfree(cs);
919 
920 	return err;
921 }
922 
923 static void s3c64xx_spi_cleanup(struct spi_device *spi)
924 {
925 	struct s3c64xx_spi_csinfo *cs = spi_get_ctldata(spi);
926 
927 	if (gpio_is_valid(spi->cs_gpio)) {
928 		gpio_free(spi->cs_gpio);
929 		if (spi->dev.of_node)
930 			kfree(cs);
931 		else {
932 			/* On non-DT platforms, the SPI core sets
933 			 * spi->cs_gpio to -ENOENT and .setup()
934 			 * overrides it with the GPIO pin value
935 			 * passed using platform data.
936 			 */
937 			spi->cs_gpio = -ENOENT;
938 		}
939 	}
940 
941 	spi_set_ctldata(spi, NULL);
942 }
943 
944 static irqreturn_t s3c64xx_spi_irq(int irq, void *data)
945 {
946 	struct s3c64xx_spi_driver_data *sdd = data;
947 	struct spi_master *spi = sdd->master;
948 	unsigned int val, clr = 0;
949 
950 	val = readl(sdd->regs + S3C64XX_SPI_STATUS);
951 
952 	if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) {
953 		clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR;
954 		dev_err(&spi->dev, "RX overrun\n");
955 	}
956 	if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) {
957 		clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR;
958 		dev_err(&spi->dev, "RX underrun\n");
959 	}
960 	if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) {
961 		clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR;
962 		dev_err(&spi->dev, "TX overrun\n");
963 	}
964 	if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) {
965 		clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
966 		dev_err(&spi->dev, "TX underrun\n");
967 	}
968 
969 	/* Clear the pending irq by setting and then clearing it */
970 	writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR);
971 	writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);
972 
973 	return IRQ_HANDLED;
974 }
975 
976 static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
977 {
978 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
979 	void __iomem *regs = sdd->regs;
980 	unsigned int val;
981 
982 	sdd->cur_speed = 0;
983 
984 	if (sci->no_cs)
985 		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
986 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
987 		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
988 
989 	/* Disable Interrupts - we use Polling if not DMA mode */
990 	writel(0, regs + S3C64XX_SPI_INT_EN);
991 
992 	if (!sdd->port_conf->clk_from_cmu)
993 		writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
994 				regs + S3C64XX_SPI_CLK_CFG);
995 	writel(0, regs + S3C64XX_SPI_MODE_CFG);
996 	writel(0, regs + S3C64XX_SPI_PACKET_CNT);
997 
998 	/* Clear any irq pending bits, should set and clear the bits */
999 	val = S3C64XX_SPI_PND_RX_OVERRUN_CLR |
1000 		S3C64XX_SPI_PND_RX_UNDERRUN_CLR |
1001 		S3C64XX_SPI_PND_TX_OVERRUN_CLR |
1002 		S3C64XX_SPI_PND_TX_UNDERRUN_CLR;
1003 	writel(val, regs + S3C64XX_SPI_PENDING_CLR);
1004 	writel(0, regs + S3C64XX_SPI_PENDING_CLR);
1005 
1006 	writel(0, regs + S3C64XX_SPI_SWAP_CFG);
1007 
1008 	val = readl(regs + S3C64XX_SPI_MODE_CFG);
1009 	val &= ~S3C64XX_SPI_MODE_4BURST;
1010 	val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1011 	val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
1012 	writel(val, regs + S3C64XX_SPI_MODE_CFG);
1013 
1014 	s3c64xx_flush_fifo(sdd);
1015 }
1016 
1017 #ifdef CONFIG_OF
1018 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1019 {
1020 	struct s3c64xx_spi_info *sci;
1021 	u32 temp;
1022 
1023 	sci = devm_kzalloc(dev, sizeof(*sci), GFP_KERNEL);
1024 	if (!sci)
1025 		return ERR_PTR(-ENOMEM);
1026 
1027 	if (of_property_read_u32(dev->of_node, "samsung,spi-src-clk", &temp)) {
1028 		dev_warn(dev, "spi bus clock parent not specified, using clock at index 0 as parent\n");
1029 		sci->src_clk_nr = 0;
1030 	} else {
1031 		sci->src_clk_nr = temp;
1032 	}
1033 
1034 	if (of_property_read_u32(dev->of_node, "num-cs", &temp)) {
1035 		dev_warn(dev, "number of chip select lines not specified, assuming 1 chip select line\n");
1036 		sci->num_cs = 1;
1037 	} else {
1038 		sci->num_cs = temp;
1039 	}
1040 
1041 	sci->no_cs = of_property_read_bool(dev->of_node, "no-cs-readback");
1042 
1043 	return sci;
1044 }
1045 #else
1046 static struct s3c64xx_spi_info *s3c64xx_spi_parse_dt(struct device *dev)
1047 {
1048 	return dev_get_platdata(dev);
1049 }
1050 #endif
1051 
1052 static inline const struct s3c64xx_spi_port_config *s3c64xx_spi_get_port_config(
1053 						struct platform_device *pdev)
1054 {
1055 #ifdef CONFIG_OF
1056 	if (pdev->dev.of_node)
1057 		return of_device_get_match_data(&pdev->dev);
1058 #endif
1059 	return (const struct s3c64xx_spi_port_config *)platform_get_device_id(pdev)->driver_data;
1060 }
1061 
1062 static int s3c64xx_spi_probe(struct platform_device *pdev)
1063 {
1064 	struct resource	*mem_res;
1065 	struct s3c64xx_spi_driver_data *sdd;
1066 	struct s3c64xx_spi_info *sci = dev_get_platdata(&pdev->dev);
1067 	struct spi_master *master;
1068 	int ret, irq;
1069 	char clk_name[16];
1070 
1071 	if (!sci && pdev->dev.of_node) {
1072 		sci = s3c64xx_spi_parse_dt(&pdev->dev);
1073 		if (IS_ERR(sci))
1074 			return PTR_ERR(sci);
1075 	}
1076 
1077 	if (!sci) {
1078 		dev_err(&pdev->dev, "platform_data missing!\n");
1079 		return -ENODEV;
1080 	}
1081 
1082 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1083 	if (mem_res == NULL) {
1084 		dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
1085 		return -ENXIO;
1086 	}
1087 
1088 	irq = platform_get_irq(pdev, 0);
1089 	if (irq < 0) {
1090 		dev_warn(&pdev->dev, "Failed to get IRQ: %d\n", irq);
1091 		return irq;
1092 	}
1093 
1094 	master = spi_alloc_master(&pdev->dev,
1095 				sizeof(struct s3c64xx_spi_driver_data));
1096 	if (master == NULL) {
1097 		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
1098 		return -ENOMEM;
1099 	}
1100 
1101 	platform_set_drvdata(pdev, master);
1102 
1103 	sdd = spi_master_get_devdata(master);
1104 	sdd->port_conf = s3c64xx_spi_get_port_config(pdev);
1105 	sdd->master = master;
1106 	sdd->cntrlr_info = sci;
1107 	sdd->pdev = pdev;
1108 	sdd->sfr_start = mem_res->start;
1109 	if (pdev->dev.of_node) {
1110 		ret = of_alias_get_id(pdev->dev.of_node, "spi");
1111 		if (ret < 0) {
1112 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
1113 				ret);
1114 			goto err_deref_master;
1115 		}
1116 		sdd->port_id = ret;
1117 	} else {
1118 		sdd->port_id = pdev->id;
1119 	}
1120 
1121 	sdd->cur_bpw = 8;
1122 
1123 	sdd->tx_dma.direction = DMA_MEM_TO_DEV;
1124 	sdd->rx_dma.direction = DMA_DEV_TO_MEM;
1125 
1126 	master->dev.of_node = pdev->dev.of_node;
1127 	master->bus_num = sdd->port_id;
1128 	master->setup = s3c64xx_spi_setup;
1129 	master->cleanup = s3c64xx_spi_cleanup;
1130 	master->prepare_transfer_hardware = s3c64xx_spi_prepare_transfer;
1131 	master->prepare_message = s3c64xx_spi_prepare_message;
1132 	master->transfer_one = s3c64xx_spi_transfer_one;
1133 	master->num_chipselect = sci->num_cs;
1134 	master->dma_alignment = 8;
1135 	master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
1136 					SPI_BPW_MASK(8);
1137 	/* the spi->mode bits understood by this driver: */
1138 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1139 	master->auto_runtime_pm = true;
1140 	if (!is_polling(sdd))
1141 		master->can_dma = s3c64xx_spi_can_dma;
1142 
1143 	sdd->regs = devm_ioremap_resource(&pdev->dev, mem_res);
1144 	if (IS_ERR(sdd->regs)) {
1145 		ret = PTR_ERR(sdd->regs);
1146 		goto err_deref_master;
1147 	}
1148 
1149 	if (sci->cfg_gpio && sci->cfg_gpio()) {
1150 		dev_err(&pdev->dev, "Unable to config gpio\n");
1151 		ret = -EBUSY;
1152 		goto err_deref_master;
1153 	}
1154 
1155 	/* Setup clocks */
1156 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
1157 	if (IS_ERR(sdd->clk)) {
1158 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
1159 		ret = PTR_ERR(sdd->clk);
1160 		goto err_deref_master;
1161 	}
1162 
1163 	ret = clk_prepare_enable(sdd->clk);
1164 	if (ret) {
1165 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
1166 		goto err_deref_master;
1167 	}
1168 
1169 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);
1170 	sdd->src_clk = devm_clk_get(&pdev->dev, clk_name);
1171 	if (IS_ERR(sdd->src_clk)) {
1172 		dev_err(&pdev->dev,
1173 			"Unable to acquire clock '%s'\n", clk_name);
1174 		ret = PTR_ERR(sdd->src_clk);
1175 		goto err_disable_clk;
1176 	}
1177 
1178 	ret = clk_prepare_enable(sdd->src_clk);
1179 	if (ret) {
1180 		dev_err(&pdev->dev, "Couldn't enable clock '%s'\n", clk_name);
1181 		goto err_disable_clk;
1182 	}
1183 
1184 	if (sdd->port_conf->clk_ioclk) {
1185 		sdd->ioclk = devm_clk_get(&pdev->dev, "spi_ioclk");
1186 		if (IS_ERR(sdd->ioclk)) {
1187 			dev_err(&pdev->dev, "Unable to acquire 'ioclk'\n");
1188 			ret = PTR_ERR(sdd->ioclk);
1189 			goto err_disable_src_clk;
1190 		}
1191 
1192 		ret = clk_prepare_enable(sdd->ioclk);
1193 		if (ret) {
1194 			dev_err(&pdev->dev, "Couldn't enable clock 'ioclk'\n");
1195 			goto err_disable_src_clk;
1196 		}
1197 	}
1198 
1199 	if (!is_polling(sdd)) {
1200 		/* Acquire DMA channels */
1201 		sdd->rx_dma.ch = dma_request_chan(&pdev->dev, "rx");
1202 		if (IS_ERR(sdd->rx_dma.ch)) {
1203 			dev_err(&pdev->dev, "Failed to get RX DMA channel\n");
1204 			ret = PTR_ERR(sdd->rx_dma.ch);
1205 			goto err_disable_io_clk;
1206 		}
1207 		sdd->tx_dma.ch = dma_request_chan(&pdev->dev, "tx");
1208 		if (IS_ERR(sdd->tx_dma.ch)) {
1209 			dev_err(&pdev->dev, "Failed to get TX DMA channel\n");
1210 			ret = PTR_ERR(sdd->tx_dma.ch);
1211 			goto err_release_rx_dma;
1212 		}
1213 	}
1214 
1215 	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1216 	pm_runtime_use_autosuspend(&pdev->dev);
1217 	pm_runtime_set_active(&pdev->dev);
1218 	pm_runtime_enable(&pdev->dev);
1219 	pm_runtime_get_sync(&pdev->dev);
1220 
1221 	/* Setup Deufult Mode */
1222 	s3c64xx_spi_hwinit(sdd);
1223 
1224 	spin_lock_init(&sdd->lock);
1225 	init_completion(&sdd->xfer_completion);
1226 
1227 	ret = devm_request_irq(&pdev->dev, irq, s3c64xx_spi_irq, 0,
1228 				"spi-s3c64xx", sdd);
1229 	if (ret != 0) {
1230 		dev_err(&pdev->dev, "Failed to request IRQ %d: %d\n",
1231 			irq, ret);
1232 		goto err_pm_put;
1233 	}
1234 
1235 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1236 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1237 	       sdd->regs + S3C64XX_SPI_INT_EN);
1238 
1239 	ret = devm_spi_register_master(&pdev->dev, master);
1240 	if (ret != 0) {
1241 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
1242 		goto err_pm_put;
1243 	}
1244 
1245 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",
1246 					sdd->port_id, master->num_chipselect);
1247 	dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
1248 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1);
1249 
1250 	pm_runtime_mark_last_busy(&pdev->dev);
1251 	pm_runtime_put_autosuspend(&pdev->dev);
1252 
1253 	return 0;
1254 
1255 err_pm_put:
1256 	pm_runtime_put_noidle(&pdev->dev);
1257 	pm_runtime_disable(&pdev->dev);
1258 	pm_runtime_set_suspended(&pdev->dev);
1259 
1260 	if (!is_polling(sdd))
1261 		dma_release_channel(sdd->tx_dma.ch);
1262 err_release_rx_dma:
1263 	if (!is_polling(sdd))
1264 		dma_release_channel(sdd->rx_dma.ch);
1265 err_disable_io_clk:
1266 	clk_disable_unprepare(sdd->ioclk);
1267 err_disable_src_clk:
1268 	clk_disable_unprepare(sdd->src_clk);
1269 err_disable_clk:
1270 	clk_disable_unprepare(sdd->clk);
1271 err_deref_master:
1272 	spi_master_put(master);
1273 
1274 	return ret;
1275 }
1276 
1277 static int s3c64xx_spi_remove(struct platform_device *pdev)
1278 {
1279 	struct spi_master *master = platform_get_drvdata(pdev);
1280 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1281 
1282 	pm_runtime_get_sync(&pdev->dev);
1283 
1284 	writel(0, sdd->regs + S3C64XX_SPI_INT_EN);
1285 
1286 	if (!is_polling(sdd)) {
1287 		dma_release_channel(sdd->rx_dma.ch);
1288 		dma_release_channel(sdd->tx_dma.ch);
1289 	}
1290 
1291 	clk_disable_unprepare(sdd->ioclk);
1292 
1293 	clk_disable_unprepare(sdd->src_clk);
1294 
1295 	clk_disable_unprepare(sdd->clk);
1296 
1297 	pm_runtime_put_noidle(&pdev->dev);
1298 	pm_runtime_disable(&pdev->dev);
1299 	pm_runtime_set_suspended(&pdev->dev);
1300 
1301 	return 0;
1302 }
1303 
1304 #ifdef CONFIG_PM_SLEEP
1305 static int s3c64xx_spi_suspend(struct device *dev)
1306 {
1307 	struct spi_master *master = dev_get_drvdata(dev);
1308 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1309 
1310 	int ret = spi_master_suspend(master);
1311 	if (ret)
1312 		return ret;
1313 
1314 	ret = pm_runtime_force_suspend(dev);
1315 	if (ret < 0)
1316 		return ret;
1317 
1318 	sdd->cur_speed = 0; /* Output Clock is stopped */
1319 
1320 	return 0;
1321 }
1322 
1323 static int s3c64xx_spi_resume(struct device *dev)
1324 {
1325 	struct spi_master *master = dev_get_drvdata(dev);
1326 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1327 	struct s3c64xx_spi_info *sci = sdd->cntrlr_info;
1328 	int ret;
1329 
1330 	if (sci->cfg_gpio)
1331 		sci->cfg_gpio();
1332 
1333 	ret = pm_runtime_force_resume(dev);
1334 	if (ret < 0)
1335 		return ret;
1336 
1337 	return spi_master_resume(master);
1338 }
1339 #endif /* CONFIG_PM_SLEEP */
1340 
1341 #ifdef CONFIG_PM
1342 static int s3c64xx_spi_runtime_suspend(struct device *dev)
1343 {
1344 	struct spi_master *master = dev_get_drvdata(dev);
1345 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1346 
1347 	clk_disable_unprepare(sdd->clk);
1348 	clk_disable_unprepare(sdd->src_clk);
1349 	clk_disable_unprepare(sdd->ioclk);
1350 
1351 	return 0;
1352 }
1353 
1354 static int s3c64xx_spi_runtime_resume(struct device *dev)
1355 {
1356 	struct spi_master *master = dev_get_drvdata(dev);
1357 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
1358 	int ret;
1359 
1360 	if (sdd->port_conf->clk_ioclk) {
1361 		ret = clk_prepare_enable(sdd->ioclk);
1362 		if (ret != 0)
1363 			return ret;
1364 	}
1365 
1366 	ret = clk_prepare_enable(sdd->src_clk);
1367 	if (ret != 0)
1368 		goto err_disable_ioclk;
1369 
1370 	ret = clk_prepare_enable(sdd->clk);
1371 	if (ret != 0)
1372 		goto err_disable_src_clk;
1373 
1374 	s3c64xx_spi_hwinit(sdd);
1375 
1376 	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
1377 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
1378 	       sdd->regs + S3C64XX_SPI_INT_EN);
1379 
1380 	return 0;
1381 
1382 err_disable_src_clk:
1383 	clk_disable_unprepare(sdd->src_clk);
1384 err_disable_ioclk:
1385 	clk_disable_unprepare(sdd->ioclk);
1386 
1387 	return ret;
1388 }
1389 #endif /* CONFIG_PM */
1390 
1391 static const struct dev_pm_ops s3c64xx_spi_pm = {
1392 	SET_SYSTEM_SLEEP_PM_OPS(s3c64xx_spi_suspend, s3c64xx_spi_resume)
1393 	SET_RUNTIME_PM_OPS(s3c64xx_spi_runtime_suspend,
1394 			   s3c64xx_spi_runtime_resume, NULL)
1395 };
1396 
1397 static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
1398 	.fifo_lvl_mask	= { 0x7f },
1399 	.rx_lvl_offset	= 13,
1400 	.tx_st_done	= 21,
1401 	.high_speed	= true,
1402 };
1403 
1404 static const struct s3c64xx_spi_port_config s3c6410_spi_port_config = {
1405 	.fifo_lvl_mask	= { 0x7f, 0x7F },
1406 	.rx_lvl_offset	= 13,
1407 	.tx_st_done	= 21,
1408 };
1409 
1410 static const struct s3c64xx_spi_port_config s5pv210_spi_port_config = {
1411 	.fifo_lvl_mask	= { 0x1ff, 0x7F },
1412 	.rx_lvl_offset	= 15,
1413 	.tx_st_done	= 25,
1414 	.high_speed	= true,
1415 };
1416 
1417 static const struct s3c64xx_spi_port_config exynos4_spi_port_config = {
1418 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F },
1419 	.rx_lvl_offset	= 15,
1420 	.tx_st_done	= 25,
1421 	.high_speed	= true,
1422 	.clk_from_cmu	= true,
1423 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1424 };
1425 
1426 static const struct s3c64xx_spi_port_config exynos7_spi_port_config = {
1427 	.fifo_lvl_mask	= { 0x1ff, 0x7F, 0x7F, 0x7F, 0x7F, 0x1ff},
1428 	.rx_lvl_offset	= 15,
1429 	.tx_st_done	= 25,
1430 	.high_speed	= true,
1431 	.clk_from_cmu	= true,
1432 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1433 };
1434 
1435 static const struct s3c64xx_spi_port_config exynos5433_spi_port_config = {
1436 	.fifo_lvl_mask	= { 0x1ff, 0x7f, 0x7f, 0x7f, 0x7f, 0x1ff},
1437 	.rx_lvl_offset	= 15,
1438 	.tx_st_done	= 25,
1439 	.high_speed	= true,
1440 	.clk_from_cmu	= true,
1441 	.clk_ioclk	= true,
1442 	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
1443 };
1444 
1445 static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
1446 	{
1447 		.name		= "s3c2443-spi",
1448 		.driver_data	= (kernel_ulong_t)&s3c2443_spi_port_config,
1449 	}, {
1450 		.name		= "s3c6410-spi",
1451 		.driver_data	= (kernel_ulong_t)&s3c6410_spi_port_config,
1452 	},
1453 	{ },
1454 };
1455 
1456 static const struct of_device_id s3c64xx_spi_dt_match[] = {
1457 	{ .compatible = "samsung,s3c2443-spi",
1458 			.data = (void *)&s3c2443_spi_port_config,
1459 	},
1460 	{ .compatible = "samsung,s3c6410-spi",
1461 			.data = (void *)&s3c6410_spi_port_config,
1462 	},
1463 	{ .compatible = "samsung,s5pv210-spi",
1464 			.data = (void *)&s5pv210_spi_port_config,
1465 	},
1466 	{ .compatible = "samsung,exynos4210-spi",
1467 			.data = (void *)&exynos4_spi_port_config,
1468 	},
1469 	{ .compatible = "samsung,exynos7-spi",
1470 			.data = (void *)&exynos7_spi_port_config,
1471 	},
1472 	{ .compatible = "samsung,exynos5433-spi",
1473 			.data = (void *)&exynos5433_spi_port_config,
1474 	},
1475 	{ },
1476 };
1477 MODULE_DEVICE_TABLE(of, s3c64xx_spi_dt_match);
1478 
1479 static struct platform_driver s3c64xx_spi_driver = {
1480 	.driver = {
1481 		.name	= "s3c64xx-spi",
1482 		.pm = &s3c64xx_spi_pm,
1483 		.of_match_table = of_match_ptr(s3c64xx_spi_dt_match),
1484 	},
1485 	.probe = s3c64xx_spi_probe,
1486 	.remove = s3c64xx_spi_remove,
1487 	.id_table = s3c64xx_spi_driver_ids,
1488 };
1489 MODULE_ALIAS("platform:s3c64xx-spi");
1490 
1491 module_platform_driver(s3c64xx_spi_driver);
1492 
1493 MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
1494 MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
1495 MODULE_LICENSE("GPL");
1496